Improvement in watchmakers  chucks



UNITED STA'rEs PATENT 'OFFIon HARRISON H. HESKETT, OF LE ROY, ILLINOIS.

IMPROVEMENT IN WATCHMAKERS' CHUCKS.

Specification forming part of Letters Patent No. 116,591, dated July 4, 1871.

` sts; and I do hereby declare that the following is a full and exact description thereof, reference being' had to the accompanying drawng and to letters of reference marked thereon making a part of this specification, in which- Figure 1 is a plan view, and Fig. 2 a longitudinal central section.

A, a cylinder, with horizontal conical hole; B, collar, With flange; C, cap, With sprhlg-head; D, spring in cap; and E, a screW-collet, With solid run.

My device is constructed by attaching the cylinder A to the spindle of a lathe, the spindle being made conicalto fit tightly therein. The cylinder has a slot to receive a strap, b, correspondingg` in size, adjusted to the inside of the cap O, the cap also being made to fit closely over the cylinder, and to screw into the flange on the collar B. A hole is cut in the end of the cap O to allow the stafl' or object to be turned to pass through. The collar B is made to fit on the shoulder of the cylinder on the inner or reverse end thereof, and is used in connection With the cap C to confine the Wheel containing the staff or the collet, as desired. The spring,` is constructed by attaching two other sina-11 flat Springs to the end of the cap C on the inside thereof, and a washer fitting into the cap is attached to other ends, and is used for the purpose of graduating the pressure on the Wheel or riln of collet, to alloW the Staff to slip to the center in revolving the chnck and pressing on it. The collet E is similar to others, except that one jaW is made solid to the rim or plate, which is necessary to secure the object, as hereinbefore stated.

I claimi The arrangeinent of the cylinder A, collar B upon the screW-threaded cap-springsD, jaws F, and face-plate C, substantially as hereinbefore described, and for the purposes set forth.

WVitnesses: H. H. HESKETT.

W. H. SoMERs, L. G. PEARL. 

